Greenhouse Farming

Greenhouse farming spans a wide spectrum of structures and technology levels, unified by the goal of moderating the crop’s growing environment relative to outdoor conditions. A simple tunnel mainly buffers wind and rain, while an advanced glasshouse can actively regulate temperature, humidity, light, and even carbon dioxide concentration.

Polytunnel / high tunnel

A low-cost, plastic-covered structure providing basic weather protection with limited climate control.

Glasshouse

A permanent, typically glass-covered structure with more extensive climate-control systems.

Climate control

Ventilation, heating, cooling, shading, and lighting systems used to regulate the internal growing environment.

Greenhouse environmental control typically combines passive and active elements: roof and side vents or fans to manage temperature and humidity, shading or supplemental lighting to manage light levels, and, in more advanced operations, heating or cooling systems and carbon dioxide enrichment to further optimize growing conditions.

• Ventilation (vents or fans) to manage temperature and humidity
• Heating or cooling systems in more advanced structures
• Shading or supplemental lighting to manage light intensity and day length
• Carbon dioxide enrichment in some intensive operations

Enclosing the growing environment changes several aspects of crop management. Irrigation is usually delivered precisely through drip systems, often combined with fertigation; pollination for crops such as tomatoes may require bees, bumblebee colonies, or mechanical assistance since wind and open-field pollinators are excluded; and pest and disease management often relies more heavily on biological control agents suited to an enclosed, humid environment.

• Extends the growing season beyond the local open-field window
• Can improve yield consistency and produce quality
• Protects crops from weather extremes and some pests
• Enables efficient, targeted input use through drip irrigation and fertigation

• Higher capital and energy costs than open-field production
• Dependence on climate-control systems and, in some cases, a reliable power supply
• Enclosed, humid conditions can favor certain diseases if not well managed
• Economically viable mainly for higher-value crops that justify the added cost

Greenhouse and protected cultivation is widespread in regions with harsh, cold, or highly seasonal climates where it extends an otherwise short growing season, and near urban markets where it supports fresh, perishable produce supply. Scale ranges from small tunnels on smallholder farms to large clusters of commercial glasshouses.